Dry treatment of ores.



WILHELM BUDDEUS, OF CHARLOTTENBUBG', GERMANY.

DRY TREATMENT OF ORES.

No Drawing.

To all whom it may concern:

Be it known that I, Dr. WILHELM BUD- onus, a subject of the Duke ofSaxe-Coburg-Gotha, and resident of Charlottenburg, German Empire, haveinvented certain new and useful Improvements Relating to the DryTreatment of Ores, of which the following is a specification.

This invention relates to the dry treatment of zinc blende, orescontaining blende, and similar metallurgical products. The roasting ofzinc blende and ore containing blende has hitherto been effected almostexclusively by disintegrating the same, in cases where it is not alreadyin a finely divided condition, and then roasting it to deadness inexternally heated furnaces. In some cases the ore in lump form .has beengiven a preliminary roasting in kilns or shaft furnaces, but hasnevertheless required to be roasted in the same furnace as is used forfinely divided ore, in order to bring it to the dead-roasted condition;Latterly, finely divided blende has been roasted in mechanical furnacesuntil the sulfur content is reduced to about 8 or 10 per cent., and hasthen been roasted to deadness in externally heated furnaces. It has alsobeen proposed to roast blende, to deadness by blowing it with air into ahighly heated chamber or by supplying highly heated air to it. In allsuch proposals, however, it is necessary that the blende to be roastedto deadness, should be in a disintegrated con' dition.

' According to the present invention the disintegrated or finely dividedore or similar material is formed into briquets, and these briquets arethen roasted to deadness. The briqueting of the ore renders it possibleto roast it in briquet form in shaft furnaces or kilns after the mannersometimes adopted with ore in coarse or lump form,

4 with the difference, however, that theporous briquets obtained by the.briqueting of finely divided ore afford a quicker and more thoroughaccess for'air than is the case with the compact ore in lump form, theresult being that, owing to the higher combustion Specification ofLetters Patent.

Application filed February 5, 1914. Serial No. 818,825.

Patented Dec. 15, 1914.

temperature attained, a more thorough roasting is obtained, the sulfurcontent be ing reduced to 1 to 2 per cent. Other fuel may be mixed withthe briquets either prior to briqueting or during the roasting, or thebriquets may be roasted to deadness by a burning gas current or by acompressed air blast.

One method of carrying the. invention into efiect consists in mixingdisintegrated or finely divided blende with a, binding agent, such forexample as calcium silicate or various other salts, and in forming themixture into briquets. The binding medium prevents the blende particlesfrom falling apart during the subsequent heating. These briquets may bedried, if necessary, and are then kindled in a suitable furnace, such asa shaft furnace, and are roasted off by the aid of a natural air draftor compressed air. The briquets can be given any desired form, beingpreferably spherical, egg-shape, or cylindrical, and equal in size. Thebriquets together with the fuel can be blown continuously into thefurnace, or can be intro duced in charges. The furnace may be providedwith a device for directing a burnv ing gas current onto the briquetsafter they have been preliminarily roasted.

Having now particularly described and ascertained the nature of my saidinvention and in what manner the same is to be performed, I declare thatwhat I claim is The treatment of zinc blende, or"e containing blende,and similar metallurgical products, consisting in. mixing the finelydivided or disintegrated material with a binding agent such as calciumsilicate, forming it into briquets, and roasting the briquets with fuelin the presence of an air current, and

finally directing a burning gas current against the briquets.

The foregoing specification signed at B rlin, this 29th day of December,1913.

DR. WILHELM BUDDEUSQ In presence of two witnesses:

HENRY Hearse, WOLDEMAR Haur'r.

